This project is designed to continue our study of the effects of LSD upon the development and maturation of the mouse brain. We will investigate the action of LSD upon the indoleamine pathway, temperature regulation and behavior, using animals exposed to the drug during gestation and the early postnatal period. Three separate drug doses will be used. For alterations in the indoleamine pathway we will measure the intermediates, 5-hydroxytryptamine (5-HT), 5-hydroxytryptophan (5-HTP) and 5-hydroxyindole acetic acid (5-HIAA) using fluorometric methods, and the pathway enzymes tryptophan-5-hydroxylase (T5-H), 5-hydroxytryptophan decarboxylase (5-HTPD) and monoamine oxidase (MAO), using in vitro radiocarbon methods. The brain will be subdivided into four fractions for these measurements. One of the functions associated with brain indoleamines is regulation of body temperature. Therefore, if LSD disrupts the normal development of indoleamine metabolism this could be manifested as altered temperature regulatory ability. Ability to regulate temperature will be assessed by exposure to mild cold stress. We will also test behavioral patterns.